As conventional push switches, there is, for example, a water resistant push switch provided on a door handle (JP-A-2004-327126). The push switch is attached into an outside handle 103 of a door lock device of a vehicle and is pressed when a user is to operate a door lock to lock or unlock a door of the vehicle.
A button 171 of the push switch is constituted by a rubber material and is formed by an operating portion 128 fitted into a handle cover 104, a thin portion 121, and a boss portion 166 protruded toward a switch 107 side below the operating portion 128.
The door switch 107 pressed against the boss portion 166 is covered with a switch cap 168 in order to ensure a water resistance and a moisture resistance. The switch cap 168 is fitted into a peripheral edge of an opening of a switch case 176 fixed to the outside handle 103, and a switch plate 177 is further fitted into the switch case 176.
When the push switch is pressed by the user, the thin portion 121 of the button 171 is deformed so that the boss portion 166 presses the switch cap 168 provided therebelow. A pressing portion 179 of the switch 107 having a water resistant structure which is provided below the switch cap 168 is pressed by the pressing force. Thus, the switch 107 is turned ON.
In that case, if an excessively great load is input as an external force to the button 171, the thin portion 121 of the button 171 is deformed and moved toward the switch side up to a position in which an end face 122 on an inside of the button 171 abuts on an end face 123 of the switch plate 177.
In the push switch, when the button 171 is pressed at an excessively great load in a vertical direction of the drawing, the end face 122 of the operating portion 128 abuts on the end face 123 of the switch plate 177 so that the pressing load acts toward a peripheral edge portion of the switch cap 168 and is transmitted to a lower part of the switch case 176, and is moved away toward a load receiving portion 126 of a body portion 132 abutting on the switch case 176. For this reason, it is assumed that the excessively great load can be prevented from acting on the pressing portion 179 of the switch 107.
However, the push switch is not always pressed only in the vertical direction of the drawing but might be pressed in every direction. For example, in the case in which the button 171 is pressed at an excessively great load in an obliquely transverse direction of the drawing, the thin portion 121 of the button 171 is extended unnecessarily or the thin portion 121 of the button 171 or the boss portion 166 collides with a corner part of an opening portion of the switch plate 177. When the pressing operation in the obliquely transverse direction of the drawing is repeated, there is a possibility that the thin portion 121 of the button 171 or the boss portion 166 might be cracked and broken.